Short answer: match the recipe’s original cooking time to the chart below (a stew that simmers 1 to 3 hours becomes 8 to 18 hours on LOW or 4 to 6 hours on HIGH), use about half the liquid, thaw the meat first, put root vegetables on the bottom, and add dairy, pasta and tender vegetables near the end. Fill the pot between half and two-thirds full.
This is for the Sunday-night planner with a favorite stovetop chili, a Dutch-oven pot roast or a soup that wants an hour of simmering, and a weekday that leaves at 8 a.m. and gets home at 6. The recipe says “simmer 90 minutes, stirring occasionally”. You want to know what to set the dial to, how much stock to pour in, and what to hold back so dinner is not soup with grey vegetables in it. October is when most of us drag the slow cooker back out, so here is the whole conversion on one page.
How long do you cook a regular recipe in a slow cooker?
Use the original recipe’s cooking time, not its prep time, and read across. This chart is from University of Missouri Extension:
| Recipe says (oven or stovetop) | Slow cooker on LOW | Slow cooker on HIGH |
|---|---|---|
| 15 to 30 minutes | 4 to 6 hours | 1½ to 2 hours |
| 30 to 45 minutes | 6 to 10 hours | 3 to 4 hours |
| 45 minutes to 3 hours | 8 to 18 hours | 4 to 6 hours |
The same source gives the shortcut behind the chart: one hour on HIGH is about two hours on LOW. Montana State University Extension’s version of the chart caps the last row at 16 hours on LOW, which is a reminder that these ranges are wide on purpose. Slow cookers differ, and a 4-quart pot that is nearly full cooks differently from a 7-quart pot that is half full.
For the working day in the example above, a chili or stew that originally simmered for an hour or two lands comfortably in the LOW range: start it at 8, eat at 6. A recipe that only cooks for 20 minutes on the stove (a quick curry, a stir-fried sauce) is a poor fit for a ten-hour day, because 4 to 6 hours on LOW is its window. Cook that one in the evening instead, or pick a different recipe for the day you are out.
Food-safety guidance from USDA (repeated by Clemson Extension) adds one tweak: if you can, run the cooker on HIGH for the first hour, then turn it down to LOW. If you are leaving the house straight away, set it to LOW and leave it.
How much liquid do you use when converting to a slow cooker?
About half of what the recipe calls for. That is the rule from Montana State University Extension. On a stovetop, a simmer boils off a good share of the liquid. Under a slow cooker’s lid almost nothing escapes, and meat and vegetables release their own juices on top. Pour in the full 4 cups of stock a stovetop chili asks for and you come home to chili soup.
Two exceptions. A soup is meant to be liquid, so keep its liquid close to the original. And a recipe that is already written for a slow cooker has had this adjustment made for it; do not halve it again.
If the result is still thin at the end, take the lid off and run it on HIGH for the last half hour, or stir in a little cornstarch mixed with cold water and let it cook until it thickens. It is easier to add a splash of stock at the end than to rescue a watery pot.
What order do you put things in?
Layering matters more in a slow cooker than in a pan, because nothing gets stirred for hours and the heat comes from the bottom and sides.
- Root vegetables first, on the bottom and around the sides. USDA guidance is that vegetables cook more slowly than meat in a slow cooker, so potatoes, carrots, onions and parsnips go in first, where the heat is.
- Thawed meat on top of the vegetables. Never put frozen meat or poultry in a slow cooker. It heats gently, and frozen meat spends too long in the temperature danger zone on the way up. If it is still frozen at breakfast, see how to thaw chicken fast and safely and cook something else tonight.
- The reduced liquid, poured over. Sauces, tomatoes and stock go on last at this stage.
- Lid on, and leave it on. Lift it only to stir or check doneness. Missouri Extension’s specialist puts the cost at about 20 extra minutes of cooking every time the lid comes off.
Browning the meat in a pan first is optional. It does not make a slow-cooker dish safer, but it adds a lot of flavor, and for ground beef it lets you pour off the fat before it ends up floating on top of your chili.
What should you add at the end instead of the start?
Ten hours is long enough to wreck some ingredients. Hold these back:
- Milk, cream, cheese and sour cream: add in the last hour. Missouri Extension notes that milk curdles over long cooking.
- Pasta: add at the end or cook it separately and stir it in, or it turns to mush (Montana State Extension).
- Tender vegetables such as peas, spinach, zucchini and green beans: the last couple of hours, or the last few minutes for leafy greens.
- Ground herbs and spices, and fresh herbs: long cooking dulls them, so taste and add more near the end. Whole spices and bay leaves can go in at the start.
Red kidney beans: never straight from the bag. Raw and undercooked kidney beans contain a natural toxin, and a slow cooker does not get hot enough to destroy it. University of Illinois Extension says to soak dried kidney beans for at least 5 hours, pour the water away, and boil them briskly in fresh water for 30 minutes before they go in the cooker. Canned kidney beans are already cooked and are fine to add as they are. For chili, canned is the easy answer.
How full should the slow cooker be?
Between half and two-thirds full, per USDA. Too empty and it can overcook and scorch; too full and the middle takes too long to heat. This is where most converted recipes go wrong without anyone noticing: a stovetop recipe for four in a 7-quart cooker can sit well under the halfway line.
If yours does not fit, scale the recipe rather than the cooking time. Our guide to doubling or halving a recipe covers what scales in a straight line and what does not. Spices and salt, for example, should go up by less than the rest when you double.
Keep the converted version so you only work it out once
The first conversion of a recipe is a best guess. Write down what you set and what you would change, or next October you will be doing the maths again.
RecipeScan is one place to keep it. To be clear: the app does not convert recipes to slow-cooker times for you. The chart above is still yours to apply. What it does:
- Gets the recipe onto your phone. Import it from the recipe’s web page, or photograph the cookbook page with Premium. Our guide to scanning a cookbook page on iPhone walks through it.
- Keeps your changes on the recipe. Long-press any step or ingredient and choose Add note. Notes are only visible to you, so “Slow cooker: LOW 9 h, 2 cups stock not 4, sour cream last hour” stays attached to the step it changes.
- Scales it to fit the pot. The servings stepper on a recipe changes the ingredient amounts, and Add all to groceries puts the scaled list on your shopping list.
Making a big pot to freeze in portions? Our batch-cooking guide covers what freezes well, how to portion it and how long it keeps. And do not reheat leftovers in the slow cooker: USDA advises reheating on the stove or in the microwave until steaming hot, then using the slow cooker only to keep it warm for serving.
Frequently asked questions
How do I convert oven time to slow cooker time?
Use the original cooking time: 15 to 30 minutes becomes 4 to 6 hours on LOW or 1½ to 2 hours on HIGH; 30 to 45 minutes becomes 6 to 10 hours on LOW or 3 to 4 hours on HIGH; 45 minutes to 3 hours becomes 8 to 18 hours on LOW or 4 to 6 hours on HIGH (University of Missouri Extension).
Is one hour on high the same as two hours on low?
Roughly, yes. University of Missouri Extension says one hour on HIGH equals about two hours on LOW. Use it as a guide, and check doneness, because slow cookers vary.
Do you reduce the liquid when converting a recipe to a slow cooker?
Yes. Use about half the liquid the original recipe calls for, because almost nothing evaporates under the lid. Soups are the exception. You can add more liquid at the end if it needs it.
Can you put frozen meat in a slow cooker?
No. USDA says to always thaw meat or poultry before it goes in. A slow cooker heats gently, and frozen meat spends too long in the danger zone on the way up.
Can you put dried kidney beans straight into a slow cooker?
No. University of Illinois Extension says to soak them for at least 5 hours, drain, and boil briskly in fresh water for 30 minutes first. A slow cooker does not get hot enough to destroy the natural toxin in raw kidney beans. Canned kidney beans are safe to add as they are.
What if the power goes out while I am at work?
If you were not home for the whole cooking time and the power went out, throw the food away, even if it looks done. That is USDA guidance, repeated by Clemson Extension.
Keep your slow-cooker version of the recipe
Save the recipe in RecipeScan, scale it to fit your pot, and pin your LOW time and liquid amount to the step as a note.
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